Elucidation of novel, alternative, fiber-reinforced iron-based pozzolanic composites as SCMs

The researchers pioneered incorporating waste materials exhibiting pozzolanic properties and waste fibers from diverse industrial/agricultural fields into the construction industry to formulate enhanced, greener supplementary cementitious composites (SCMs). This research focused objectively on the formulation/evaluation of low-CO2-embodied greener construction materials known as “novel, alternative, fiber-reinforced iron-based binary/ternary pozzolanic composites (abbreviated as NAFRIC)”. The composites incorporated iron powder (Fe), metakaolin (MK), pulverized fly ash (PFA), ground granulated blastfurnace slag (GGBS), palm ash, silica fume, and limestone, which are anticipated to absorb CO2 while producing siderite (ferrous carbonate FeCO3). All the NAFRIC mixes formulated in this study demonstrated up to 4–13% improvement in compressive strength and 70–130% in flexural strength with an enhanced rupture modulus/post-crack ductility. The ternary pozzolanic iron-based fiber-reinforced concrete (FRC) composites containing 8% MK + 10% PFA + 10% GGBS and steel/polypropylene/polyethylene terephthalate (PET) fibers performed the best with attaining up to 70 MPa compressive and up to 8.9 MPa flexural strengths. The sulfate testing evaluated the durability of NAFRIC SCMs formulated in a 1:2:3 ratio better than cement concrete control mix with a 1:1:3 ratio. NAFRIC specimens demonstrated minimal surface deterioration/elongation and negligible/no strength reduction after 270 days of concentrated sulfate attack. The microstructural analysis using X-ray diffraction/fluorescence, scanning electron microscopy/energy-dispersive analysis with X-ray spectroscopy supported the strength and durability parameters by showing minimal/no ettringite formation and increased calcium silicate hydrates gel formation due to the use of FeCO3 and pozzolans. The study demonstrated the sustainable use of these better-performing NAFRIC SCMs with 10–12% reduced embodied CO2 as eco-friendly high-strength SCMs with enhanced engineering/environmental benefits

Effect of interventions to reduce malaria incidence among military personnel on active duty: study protocol for a cluster randomised controlled trial of the impact of etofenprox-treated uniforms, permethrin-treated uniforms and DEET insect repellent

BACKGROUND: While there is strong evidence that bite protection methods such as permethrin-treated clothing and topical insect repellents are protective against insect bites, there are few studies assessing the impact on malaria infection. This study will estimate the protective efficacy of treated uniforms and DEET insect repellent on the incidence of malaria infection among military personnel in an operational setting. Permethrin-treated uniforms used with DEET lotion will be compared to etofenprox-treated uniforms with DEET lotion. The effect of DEET lotion will be estimated by comparing permethrin-treated uniforms with DEET or placebo lotion. METHOD: A cluster randomised double-blind placebo-controlled trial is planned to evaluate the effectiveness of the interventions on preventing malaria infections in soldiers on active duty at Mgambo National Service Camp in Tanga, Tanzania. The arms are (1) permethrin-treated uniform with 30% DEET liposome formula; (2) permethrin-treated uniform with placebo lotion; (3) candidate insect repellent system, i.e. etofenprox-treated uniform with 30% DEET liposome formula; and (4) placebo, i.e. untreated uniforms with placebo lotion. The primary outcome is the incidence of Plasmodium falciparum malaria infection detected by polymerase chain reaction (PCR) by active case detection using surveys every 2 weeks for 12 months. Rapid diagnostic tests will be used for the diagnosis of participants with symptoms. The unit of randomisation will be combania: companies formed by recruits aged 18 to 25 years; combania do activities together and sleep in the same dormitory. Unequal randomisation will be used to optimise statistical power for the primary comparison between permethrin-treated uniforms with DEET and etofenprox-treated uniforms with DEET. DISCUSSION: This trial will provide the estimate of the effects of permethrin with DEET compared to those of the new fabric treatment etofenprox with DEET and any additional effect of using DEET. The results will inform strategies to protect military personnel and civilians who have more outdoor or occupational malaria exposure than the general public. TRIAL REGISTRATION: ClinicalTrials.gov NCT02938975

Antimicrobial and brine shrimp toxicity of some plants used in traditional medicine in Bukoba District, north-western Tanzania

Herbal medicines constitute a potentially important resource for new and safe drugs for the management of microbial infections and other diseases. In this study, dichloromethane, ethylacetate and ethanol extracts of Canarium schweinfurthii Engl., Dissotis brazzae Cong., Iboza urticifolia (Bak) E.A.Bruce, Isoglosa lacteal Lindau, Strombosia Scheffleri Engl., and Whitfieldia elongate T. Anders were tested for antimicrobial activity and brine shrimp toxicity. The objective was to validate claims that they are used to treat bacterial infections, diarrhoea and heal wounds among the Haya tribe of north-western Tanzania. At least one extract of each plant showed antibacterial activity. Dichloromethane extracts were the most active while ethanol extracts were the least active. Extracts of Whitfieldia elongate and Isoglossa lacteal were the most and least active with MICs in the range 0.08-0.62 mg/ml and 15.6-62.5 mg/ml, respectively. The dichloromethane extract of Whitfieldia elongate exhibited strong antifungal activity against Cryptococcus neoformans. Against brine shrimp larvae, the extracts from the six plants exhibited a low to very low toxicity with LC50 values ranging from 15.35-374.0µg/ml. However, ethanol extracts of Dissotis brazzae and Strombosia scheffleri had LC50 values of >1000µg/ml. The seemingly innocuous nature and relatively good antibacterial activity against skin infections and gastrointestinal pathogenic bacteria support the traditional uses of the plants and deserve more detailed studies

Genetic polymorphism and evidence of signatures of selection in the Plasmodium falciparum circumsporozoite protein gene in Tanzanian regions with different malaria endemicity

Background In 2021 and 2023, the World Health Organization approved RTS,S/AS01 and R21/Matrix M malaria vaccines, respectively, for routine immunization of children in African countries with moderate to high transmission. These vaccines are made of Plasmodium falciparum circumsporozoite protein (PfCSP), but polymorphisms in the gene raise concerns regarding strain-specific responses and the long-term efficacy of these vaccines. This study assessed the Pfcsp genetic diversity, population structure and signatures of selection among parasites from areas of different malaria transmission intensities in Mainland Tanzania, to generate baseline data before the introduction of the malaria vaccines in the country. Methods The analysis involved 589 whole genome sequences generated by and as part of the MalariaGEN Community Project. The samples were collected between 2013 and January 2015 from five regions of Mainland Tanzania: Morogoro and Tanga (Muheza) (moderate transmission areas), and Kagera (Muleba), Lindi (Nachingwea), and Kigoma (Ujiji) (high transmission areas). Wright’s inbreeding coefficient (Fws), Wright’s fixation index (FST), principal component analysis, nucleotide diversity, and Tajima’s D were used to assess within-host parasite diversity, population structure and natural selection. Results Based on Fws (< 0.95), there was high polyclonality (ranging from 69.23% in Nachingwea to 56.9% in Muheza). No population structure was detected in the Pfcsp gene in the five regions (mean FST = 0.0068). The average nucleotide diversity (π), nucleotide differentiation (K) and haplotype diversity (Hd) in the five regions were 4.19, 0.973 and 0.0035, respectively. The C-terminal region of Pfcsp showed high nucleotide diversity at Th2R and Th3R regions. Positive values for the Tajima’s D were observed in the Th2R and Th3R regions consistent with balancing selection. The Pfcsp C-terminal sequences revealed 50 different haplotypes (H_1 to H_50), with only 2% of sequences matching the 3D7 strain haplotype (H_50). Conversely, with the NF54 strain, the Pfcsp C-terminal sequences revealed 49 different haplotypes (H_1 to H_49), with only 0.4% of the sequences matching the NF54 strain (Hap_49). Conclusions The findings demonstrate high diversity of the Pfcsp gene with limited population differentiation. The Pfcsp gene showed positive Tajima’s D values, consistent with balancing selection for variants within Th2R and Th3R regions. The study observed differences between the intended haplotypes incorporated into the design of RTS,S and R21 vaccines and those present in natural parasite populations. Therefore, additional research is warranted, incorporating other regions and more recent data to comprehensively assess trends in genetic diversity within this important gene. Such insights will inform the choice of alleles to be included in the future vaccines

Switches of SOX17 and SOX2 expression in the development of squamous metaplasia and squamous intraepithelial lesions of the uterine cervix

Aims: The dynamics and topographical distribution of SOX17 and SOX2 expression was studied in the transformation zone (TZ) of the uterine cervix. This TZ is a dynamic area where switches from glandular into squamous epithelium can be recognized, new squamocolumnar junctions are formed, and premalignant lesions originate. SOX17 and SOX2 show mutually exclusive expression patterns in the normal uterine cervix, with SOX2 being exclusively found in squamous epithelium, while SOX17 is detected in endocervical columnar cells and reserve cells. Methods and Results: Normal cervices and squamous intraepithelial lesions (SIL) were studied with immunohistochemistry, methylation of SOX17, human papilloma virus (HPV) genotyping, and in situ hybridization. In the TZ squamous metaplasia originating from these reserve cells can still show SOX17 expression, while also remnants of SOX17-positive immature metaplasia can be recognized in the normal squamous epithelium. SOX17 expression is gradually lost during maturation, resulting in the exclusive expression of SOX2 in the majority of (SIL). This loss of SOX17 expression is independent of methylation of the CpG island in its promotor region. HPV can be detected in SOX17-positive immature metaplastic regions in the immediate vicinity of SOX2-positive SIL, suggesting that switches in SOX17 and 2 expression can occur upon HPV infection. Conclusions: This switch in expression, and the strong association between the distribution of reserve cells and squamous areas within the columnar epithelium in the TZ, suggests that reserve cell proliferations, next to basal cells in the squamous epithelium, are potential targets for the formation of squamous lesions upon viral infection

The Role of Lifelong Learning in Political Stability and Non-Violence: Evidence from Africa

Purpose – Education as a weapon in the fight against conflict and violence remains widely debated in policy and academic circles. Against the background of growing political instability in Africa and the central role of the knowledge economy in 21st century development, this paper provides three contributions to existing literature. It assesses how political stability/ non-violence is linked to the incremental, synergy and lifelong learning effects of education. Design/methodology/approach – We define lifelong learning as the combined knowledge acquired during primary, secondary and tertiary education. Principal component analysis is used to reduce the dimensions of educational and political indicators. An endogeneity robust dynamic system Generalized Methods of Moments is used for the estimations. Findings – We establish three main findings. First, education is a useful weapon in the fight against political instability. Second, there is an incremental effect of education in the transition from secondary to tertiary schools. Third, lifelong learning also has positive and synergy effects. This means that the impact of lifelong learning is higher than the combined independent effects of various educational levels. The empirical evidence is based on 53 African countries for the period 1996-2010. Practical implications – A plethora of policy implications are discussed, inter alia: how the drive towards increasing the knowledge economy through lifelong learning can be an effective tool in the fight against violence and political insurgency in Africa. Originality/value – As the continent is nursing knowledge economy ambitions, the paper is original in investigating the determinants of political stability/non violence from three dimensions of education attainment: the incremental, the lifelong learning and a synergy effect

Chronic suppurative otitis media in Tanzanian school children and its effects on hearing

Objectives: To compare different treatment regimens of chronic suppurative otitis media (CSOM) in school children, in regard to their consequence in hearing and discharge from the ear drum perforation. Design: Randomised controlled trial. Setting: Randomly selected primary schools within Dar es Salaam. Subjects: Three hundred and twenty eight children between 5-17 years of age with CSOM in one or both ears. Results: Three to four months after the onset of treatment 31% of group 1, 54% of group 2, and 56% of group 3, had dry ears. Treatment with dry mopping and boric acid in alcohol ear drops was significantly better than dry mopping alone. Adding amoxicillin to the treatment did not improve the end results. Hearing test performed before and after treatment showed that the hearing thresholds were the same or better after the treatment. The possible risk that boric acid in alcohol ear drops should lead to sensorineural hearing loss has not been confirmed. Conclusion: Based on the above results, the treatment of choice for CSOM in children in Dar es Salaam should be dry mopping and boric acid in spirit ear drops. East African Medical Journal Vol. 83(6) 2006: 322-32

A one-year prospective study on the occurrence of traumatic spinal cord injury and clinical complications during hospitalisation in north-east Tanzania

Background: Clinical complications following spinal cord injury are a big concern as they account for increased cost of rehabilitation, poor outcomes and mortality. Objective: To describe the occurrence of traumatic spinal cord injury and associated clinical complications during hospi- talisation in North-East Tanzania. Method: Prospective data were collected from all persons with traumatic spinal cord injury from North-East Tanzania from their admission to discharge from the hospital. Neurological progress and complications were assessed routinely. Data were captured using a form that incorporated the components of the core data set of the International Spinal Cord Society and were analysed descriptively. Results: A total of 87 persons with traumatic spinal cord injury were admitted at the hospital with a mean age of 40.2 ± 15.8 years. There were 69 (79.3%) males, and 58 (66.6%) of the injuries resulted from falls. Spasms (41 patients, 47.1%), neuropathic pain (40 patients, 46%), and constipation (35 patients, 40.2%) were the most commonly reported complications. The annual incidence rate in the Kilimanjaro region was at least 38 cases per million. Conclusion: The incidence of traumatic spinal cord injury in the Kilimanjaro region is relatively high. In-hospital compli- cations are prevalent and are worth addressing for successful rehabilitation

Antimicrobial and brine shrimp toxicity of some plants used in traditional medicine in Bukoba District, north-western Tanzania

Herbal medicines constitute a potentially important resource for new and safe drugs for the management of microbial infections and other diseases. In this study, dichloromethane, ethylacetate and ethanol extracts of Canarium schweinfurthii Engl., Dissotis brazzae Cong., Iboza urticifolia (Bak) E.A.Bruce, Isoglosa lacteal Lindau, Strombosia Scheffleri Engl., and Whitfieldia elongate T. Anders were tested for antimicrobial activity and brine shrimp toxicity. The objective was to validate claims that they are used to treat bacterial infections, diarrhoea and heal wounds among the Haya tribe of north-western Tanzania. At least one extract of each plant showed antibacterial activity. Dichloromethane extracts were the most active while ethanol extracts were the least active. Extracts of Whitfieldia elongate and Isoglossa lacteal were the most and least active with MICs in the range 0.08-0.62 mg/ml and 15.6-62.5 mg/ml, respectively. The dichloromethane extract of Whitfieldia elongate exhibited strong antifungal activity against Cryptococcus neoformans. Against brine shrimp larvae, the extracts from the six plants exhibited a low to very low toxicity with LC50 values ranging from 15.35-374.0μg/ml. However, ethanol extracts of Dissotis brazzae and Strombosia scheffleri had LC50 values of >1000μg/ml. The seemingly innocuous nature and relatively good antibacterial activity against skin infections and gastrointestinal pathogenic bacteria support the traditional uses of the plants and deserve more detailed studies